Method of forming thin metal panels having bifurcated edges



Nov. 28, 1961 H. A. FROMSON 3,010,202

METHOD OF FORMING THIN METAL PANELS HAVING BIFURCATED EDGES Filed March10, 1958 T134" I I- ATTORNEYS United States Patent "ice 3,010,202 METHODOF FORMING THIN METAL PANELS HAVING BIFURCATED EDGES Howard A. Fromson,Weston, Conm, assignor to Calumet & Hecla, Inc., a corporation ofMichigan Filed Mar. 10, 1958, Ser. No. 720,382 2 Claims. (Cl. 29-533)The present invention relates to a novel and improved method of makingthin metal sheets having bifurcated edges at the sides thereof.

An object of the present invention is to provide an economical andpractical method of making thin metal sheets having bifurcationsextending lengthwise along one or both of the sheet edges from whichpanels suitable for use as siding or roofing may be formed. When used asroofing or siding panels, such sheets or panels may have a thickness ofthe order of .030 inch and hence are too thin to be slit in such form.However, in accordance with the present invention, sheets of suchthickness having bifurcated edge flaps with a combined thickness equalto the thickness of the sheet can be readily formed integrally with thesheet or panel at very little expense in addition to the usual rollingcosts.

Other objects and advantages of the invention will be apparent from thefollowing description and the accompanying drawings in which:

FIG. 1 is a perspective view illustrating a portion of a slab of metalprior to treatment in accordance with the present invention;

FIG. 2 is a perspective view of a portion of the slab shown in FIG. 1after a side edge thereof is slit in accordance with the presentinvention;

FIG. 3 is a perspective view of a sheet having a bifurcated edgeproduced from the slab shown in FIG. 2 in accordance with the invention;

FIG. 4 is an enlarged section of the bifurcated edge of the sheet shownin FIG. 3;

FIG. 5 is an enlarged section illustrating a use of the sheet shown inFIG. 3; and

FIG. 6 is a schematic view illustrating the sheet shown in FIG. 3 usedas siding or roofing.

Referring to the drawings in detail, FIG. 1 shows a slab 10 of metalwhich may be of any desired dimensions as to length, width, andthickness.

In carrying out the present invention, a slit 11 of the desired depth isfirst cut in one or both of the side edges extending lengthwise of theslab, as illustrated in FIG. 2, by means of a cutting tool. The width ofthe slit will depend on the thickness of the cutting tool, but it isdesirable to make the cut as narrow as possible to prevent wastage ofmetal.

In cutting the slit, a heavy lubricating oil may be applied to thecutting tool so as to provide the opposing surfaces of the slit with acoating of lubricating oil which will prevent bonding of such surfacesduring subsequent rolling operations. However, if desired, a coating ofa suitable resist or stop-off, such as graphite or the like, may beapplied separately to the opposing surfaces of the slit for thispurpose.

It should also be noted that the slit can be located at any desiredpoint between the upper and lower surfaces of the sheet and that bothside edges of the slab may be slit if desired.

3,010,202 Patented Nov. 28, 1961 After the slit 11 has been cut in theside edge of the slab 10, the slab is then rolled in a lengthwisedirection in the usual manner between conventional pressure rolls whichsimultaneously elongates and reduces the thickness of the slab. Therolling is continued until a sheet 10a of the desired final thicknesshas been produced. During the rolling, the opposing surfaces of the slitare brought into contact but due to the coating remain unbonded as theentire slab is elongated and reduced in thickness.

When the rolling has been completed, the side edge of the sheet has twointegral bifurcations or flaps 12 and 13 extending lengthwise along theside edge thereof and the combined thickness of the two flaps is equalto the final thickness of the sheet. Further, the relative position ofthe slit defining the flaps with respect to the upper and lower surfacesof the sheet will be the same as the position of the slit cut in theslab relative to the surfaces thereof.

As shown in FIGS. 4 and 5, the flaps at the edge of the sheet or panelmay be separated so that a nail 14 can be driven through the lower flapto secure the sheet to a support 15. As illustrated in FIG. 6, the edgeof an adjacent sheet or panel may be inserted and held between the flapswhen a sheet or panel is nailed to supports with a weatherproof jointbeing formed adjacent sheets or panels as would be desirable when thesheets are used for roofing or siding.

Another way of forming a thin metal sheet or panel having a bifurcatededge is described and claimed in my copending application S.N. 629,330,filed December 19, 1956, now Patent No. 2,828,533, for Method of FormingIntegral Sheet and Tubing Products. However, the present invention doesnot require the use of a tube or the cladding of the tube to a strip ofmetal as disclosed in said application.

It will be understood that various modifications and changes may be madein carrying out the invention as described and illustrated hereinwithout departing from the scope of the following claims.

I claim:

1. The method of producing a thin sheet metal panel having a fiat bodywith a bifurcated edge extending along one side thereof which comprisescutting a narrow slit in a vertical side of a slab of metal and alongthe length thereof and coating opposing surfaces of said slit with aresist to prevent bonding of said surfaces; and then rolling said slabbetween a set of pressure rolls into an elongated panel of thin sheetmetal.

2. The method of forming a thin sheet metal panel as defined in claim 1wherein the opposing surfaces of the slit are simultaneously coated witha resist in the form of a lubricating oil during the cutting of saidslit.

References Cited in the file of this patent UNITED STATES PATENTS677,986 Hobel July 9, 1901 1,714,479 Williams May 21, 1929 1,771,386Williams July 22, 1930 1,884,440 Welch Oct. 25, 1932 2,045,025Richardson June 23, 1936 2,690,002 Grenell Sept. 28, 1954 2,740,188Simmons Apr. 3, 1956 2,836,884 Graham June 3, 1958 2,887,762 Dobell May26, 1959

